Thread-tension-releasing device for sewing-machines



(No Model.)

, E. M. STAPLES. THREAD TENSION RELEASING DEVICE FOR SEWING MACHINES.

No. 434,002. Patented Aug. 12,1890.

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ELIAL M. STAPLES, OF ELIZABETH, NEl/V JERSEY, ASSIGNOR TO THE SINGER MANUFACTURING COMPANY OF NEW JERSEY.

THREAD-TENSION-RELEASING DEVICE FOR SEWING-MACHINES.

SPECIFICATION forming part of Letters Patent No. 434,002, dated August 12, 1890.

Application filed May 16, 1890- Serial No. 352,025. (No model.)

To aZZ whom/it mayconcern:

Be it known that I, ELIAL M. STAPLES, a citizen of the United States, residing at Elizabeth, in the county of Union and State of New Jersey, have invented certain new and useful Improvements in Sewing Machine Tension-Releases, of which the following is a specification, reference being had therein to the accompanying drawings.

My invention relates to that class of tensionreleasing devices operated from the presserfoot lifter when the presser-foot is raised from the work, the object of my invention being to provide a tension-release of this character which may be applied to sewing-machines as at present constructed without changing any of the parts of the tension device. To this end I provide the face-plate of the machine with a hole in which is loosely fitted a sliding pin, the rear tapered or rounded end of which projects into the path of the lifting-lever when the latter is raised, and the forward end of which is provided with a flange arranged to engage the outer tension disk or plate and force it away from its co-operating bearingsurface, thus leaving the thread free to be drawn through the tension device.

In the drawings, Figure l is a front view of the face-plate or head of the sewing-machine provided with my invention. Fig. 2 is a partial rear view of the same. Fig. 3 is a detailed section. Fig. 4 is a detail illustrating a slightly-modified form of my invention.

The tension device herein shown consists of an ordinary pair of tension-disks 2 mounted on a pin 3, the outer of said disks being pressed upon by a spring 4, and the latter being held upon said pin by the regulatingnut 5. Closely adjacent to the periphery of said tension-disks the face-plate 6 is provided with ahole, in which is loosely fitted a sliding pin 7, the rear end of said pin being preferably tapered or rounded, as shown, and the forward end of said pin being provided with a flange or lip 8, which is in contact with the outer tension-disk. The said pin is so arranged that its inner tapered or rounded end is in the path of movement ofthe cam of the presser foot 'lifting lever 9, so that when the said lever is raised to the position indicated by dotted lines in Fig. 2 the said pin will be pressed outward, as represented in Fig. 3, so as to tilt or force outward the outer tensiondisk and thus release the thread from the pressure thereof.

Instead of tapering or rounding the inner end of the pin 3, it is obvious that the said end may be square or beveled, and the presser-foot lifter may also be beveled, all as shown in Fig. 4.

I am aware that it is not new, broadly, to release or lift the outer tension-disk from its co-operating disk or friction-surface by means of a horizontally-sliding pin operated by the presser-foot lifter; but in thedevices of this character as heretofore made some special construction of the tension device different from that usually employed was. required. My improved tension-releasing device may be applied to sewing-machines now in use sim- 7o ply by boring a hole in the face-plate adjacent to the tension device and placing in the hole the sliding pin 7, constructed and arranged as herein shown and described.

lVhen the presser-foot is lowered by turning the lifting-lever down to its normal position, as shown by full lines in Fig. 2, the spring 4 instantly restores the outer tensiondisk to its operative position, the pressure of the spring, acting through said disk, also forc- 8o ing the pin 7 inward in position to be acted upon when the lifting-lever is next raised.

I claim- 1. The combination, with a sewing-machine tension device consisting of two disks or plates, a pin on which said disks or plates are mounted, and a spring for forcing the said disks orplates in contact with each other, of a presser-foot-lifting lever and a sliding pin provided with a lip or flange to engage the rim of the outerof said disks or plates and having its inner end arranged in the path of movement of the said lifting-lever when the latter is raised, substantially asset forth.

2. The combination, with the tension-disks, the rim of the outer of the said disks, subthe pin on which said disks are mounted, and stantially as set forth. 10 the spring for forcing the same together, of In testimony whereof I affix my signature the presser-foot-lifting lever and the sliding in presence of two witnesses.

5 pin 7 having a rounded or beveled rear end ELIAL M. STAPLES. [L. S'.]

arranged in the path of movement of the said Witnesses: lifting-lever, and provided near its outer end 5 JAMES G. GREENE,

with a flange 8 engaging the inner edge of J. G. COLEMAN. 

